Liquid-reservoir hairbrushes and combs have been available for years. In addition to combing and brushing, these devices allow a user to distribute water and oil-based liquids over the user's scalp and/or through the user's hair. In some of these devices, liquid nozzles are located at the body of the hair device or at the base of the bristles, so the liquid disperses from the nozzles initially distributed over and though the hair and only then can disperse over the user's scalp. In other devices specifically designed to disperse the liquid over the user's scalp, the nozzles are located at the distal ends of the comb teeth or hairbrush bristles. Thus, the liquid in these devices is initially distributed over the scalp and does not wet the hair.
If the nozzles are located at the bristle's ends and designed to disperse the liquid over a user's scalp, the bristle design should allow the user to manually control the amount of the liquid which disperses from the bristles during hair-brushing. Whereas pumps were used in some devices to force and control the liquid flow dispensed from the nozzles, in some other prior art devices roller-ball nozzles with absorbent feed rods that depend on capillary action were used.
Initially invented for roller-ball pens, roller-ball nozzles with absorbent feeders relied on capillary action to prevent a natural outflow of the low-viscosity liquid from the roller-ball nozzle. However, since compared to a pen, the hairbrush bristle needs to disperse a much greater volume of liquid, prior art bristles with capillary action nozzles have great difficulty in dispersing a sufficient amount of liquid over the users' scalp during hair-brushing. There are also numerous ball point and roller-ball pen tips, including gel roller-ball pen tips, but all of these either use a high viscosity oil based ink and/or capillary action to disperse the ink from the roller-ball nozzle.
Furthermore, air needs to enter the brush liquid reservoir from outside to equalize the air pressure so that liquid can be dispersed from the roller-ball nozzle. Thus, it is important that liquid-dispensing hairbrush bristles have the capacity for air to move from outside the liquid reservoir into the liquid reservoir as liquid leaves the reservoir, and at the same time have the ability to dispense a sufficient amount of the liquid over the user's scalp during hair-brushing.
However, neither current designs of liquid-dispensing bristles nor ball point and roller-ball pen tips have this capability. Thus, prior art bristles fail to achieve acceptable results for dispersing low viscosity liquids over the user's scalp during hair-brushing.